"A bird’s next on the ground” is an East Texas saying. Finding a nest on the ground is lucky—you don’t have to climb a tree to find the eggs. The following is a correspondence form an American Dialect Society colleague who lived in East Texas:
“Re: An East Texas slogan: ‘has become his own bluebird on the ground.’ In black East Texas, the saying is: ‘has got a bird’s nest on the ground.’ It’s one of my mother’s most annoying sayings, inasmuch as she never fails to credit it to her father, “As Daddy used to say, ‘You’ve got a bird’s nest on the ground.’” FWIW, her father was born in 1877.
25 September 1949, Galveston (TX) Daily News, “Mark Trail” cartoon, pg. 39:
PREFERRING SWAMPS AND BOGS, THE “MARSH” OWL BUILDS ITS NEST ON THE GROUND AND SELDOM PERCHES IN TREES…
(This cite may or may not be relevant—ed.)
22 March 1975, Port Arthur (TX) News, “Don Meredith the actor—the only way is up,” pg. 16:
Dandy Don, once described by a member of the press as resident humorist, country philosopher and sometime Cosell-baiter during four seasons on ABC’s Monday Night Football, has become his own bluebird on the ground—an East Texas slogan meaning he doesn’t have to climb the tree to pick the eggs anymore.